Mobile socket duplicate points

[mattrasband]

On mobile browsers, it appears that there may be some duplicate line drawing not only doubling the size of the dataset, but distorting the flight path (drawing a long back from the end to the beginning)

[mattrasband]

I believe this is due to socket disconnect and reconnection resending all the points without clearing the dataset. We can either check for duplicates or clear out on connection and rebuilding with the new data set.